This section provides background information related to the present disclosure which is not necessarily prior art.
Hydraulic tensioners are used for applying tension against a chain or belt for preventing chain rattle or belt slippage in an auxiliary drive system of an engine or in other industrial machines. In a typical hydraulic tensioner 100, as shown in FIG. 3, a plunger 102 is disposed within a cavity 104 of a housing 106 and is biased against a tensioner shoe 108 for applying a tension force against a belt or chain. A high pressure oil is introduced into the cavity for damping movement of the plunger. The oil is forced from the high-pressure chamber where it passes around the plunger 102 and into the chain cavity. In an inverted installation, gravity can pull the oil from the high-pressure chamber 104 (as illustrated by the arrows “A”), creating a high-pressure chamber that is starved for oil after an engine sits for some time. Accordingly, it is desirable to provide a hydraulic chain tensioner that does not drain out when installed in an inverted application.
According to the present disclosure, a hydraulic chain or belt tensioner is provided with an oil reservoir for inverted installations. The reservoir is added to the tensioner such that as oil is forced out of the high-pressure chamber the reservoir receives the oil and will hold oil within the high-pressure chamber during shutdown. The reservoir will maintain a sufficient level of oil in the high-pressure chamber to prevent startup chain rattle and inconsistent oil column stiffness.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.